This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A264516 #6 Apr 21 2021 13:45:52 %S A264516 2,2,42,228,1644,10368,65182,414414,2603670,16540506,104489208, %T A264516 662121980,4188014160,26506383680,167699955140,1061128778004, %U A264516 6714156638826,42483540261942,268814679252084,1700917160828256,10762539724166324 %N A264516 Number of (n+1) X (4+1) arrays of permutations of 0..n*5+4 with each element having directed index change -1,0 0,2 -1,-2 or 1,0. %C A264516 Column 4 of A264520. %H A264516 R. H. Hardin, <a href="/A264516/b264516.txt">Table of n, a(n) for n = 1..210</a> %H A264516 R. H. Hardin, <a href="/A264516/a264516.txt">Empirical recurrence of order 84</a> %F A264516 Empirical recurrence of order 84 (see link above) %e A264516 Some solutions for n=4 %e A264516 ..5..6..0..8..9....7..8..0..1..2....7..6..9..1..2....7..8..0..1..2 %e A264516 .12..1..2..3..4...12.13.14..3..4....0.13..5..3..4...12.11.14..3..4 %e A264516 .17.18..7.11.19....5..6.19.18..9...17.18.10..8.12....5..6.19.18..9 %e A264516 .10.23.24.13.14...10.11.24.23.17...22.11.24.23.14...10.23.24.13.17 %e A264516 .15.16.20.21.22...15.16.20.21.22...15.16.20.21.19...15.16.20.21.22 %Y A264516 Cf. A264520. %K A264516 nonn %O A264516 1,1 %A A264516 _R. H. Hardin_, Nov 16 2015